What procedure does Kevin need to perform to protect the building from unlawful entry after working late?

Setting the security alarm is essential for protecting the building from unlawful entry after hours. By activating the alarm system, Kevin ensures that any unauthorized access to the premises will trigger an alert, which can help deter potential intruders and notify security personnel. Alarm systems often come with additional features, such as surveillance cameras and motion detectors, which can provide an extra layer of safety and monitoring.

While other options, such as turning off the lights, logging off the computer, or locking filing cabinet drawers, contribute to general office security and organization, they do not directly prevent unauthorized entry into the building. The act of setting the security alarm is a key procedural step specifically designed to secure the facility after hours effectively.